Problem_updating_Pi_4Jan2015

pi@MarkPi ~ $ sudo apt-get update
sudo: unable to resolve host MarkPi
Err http://mirrordirector.raspbian.org wheezy Release.gpg
  Temporary failure resolving 'mirrordirector.raspbian.org'
Err http://raspberrypi.collabora.com wheezy Release.gpg
  Temporary failure resolving 'raspberrypi.collabora.com'
Err http://archive.raspberrypi.org wheezy Release.gpg
  Temporary failure resolving 'archive.raspberrypi.org'
Reading package lists... Done
W: Failed to fetch http://mirrordirector.raspbian.org/raspbian/dists/wheezy/Release.gpg  Temporary failure resolving 'mirrordirector.raspbian.org'

W: Failed to fetch http://raspberrypi.collabora.com/dists/wheezy/Release.gpg  Temporary failure resolving 'raspberrypi.collabora.com'

W: Failed to fetch http://archive.raspberrypi.org/debian/dists/wheezy/Release.gpg  Temporary failure resolving 'archive.raspberrypi.org'

W: Some index files failed to download. They have been ignored, or old ones used instead.